Add the verify of network_id in _test_create_interface_by_port_id

When create interface by port_id,
not only iface['port_id'] is equal to port_id,
but also iface['net_id'] should be same with network_id.

I think only check iface['port_id'] is not enough.

Change-Id: I82b53a996e8a3c1945fd16a7cf10ee85850be60d
1 file changed